result depending input

Hi,

i´m modelling a thermal problem with use of a groundwater heat pump.
So i need the infiltration temperature, which depends on the extraction temperature.
Is there a possibilty to create a boundary condition 1st type, which calculates the temperature potential from the results of the heat modeling on a different location? The results can be from the former time step.

thanks for help.

Falk

There is a plug-in for FEFLOW available from DHI-WASY for free for this purpose (called OpenLoop). Please see http://www.feflow.info/62.html for details.

hi,
thanks for answering.
but there are two different problems. First a boundary condition 1st type produces ( shown in budget analyzer) a additional heat input because of "boundary condition 1st type". i think the reason is heat conduction and heat dispersion. so i create a small area around the boundary condition with material proporties of heat conductivity and dispersivity of 0. is this a possibility to manage the problem?
Second two simulate more than one heating period, without the open loop plug in, i have to use a continious time series. So a incorrect boundary condition is used in the period of no groundwater infiltration. is this recommended in the open loop plug in or is there a possibility to consider this?

Thanks for responses.

Falk

You might run into stability problems with conductivity and dispersivity of 0 - but it is worth a try.
In case of time periods without pumping, you would have to constrain the application of the heat-transport bc by using time-varying constraints on the boundary condition. In the most general case, you can use two additional time series for the min and max constraints having 0 values when the bc should be shut off and very high (max) / very low (min) values all other times. The OpenLoop module takes care of this and switches the bc off in case of no flow.

Hi Peter,

thank you very much for the fast and serious answers.
If I use the openloop tool, I don´t have to reduce the conductivity and dispersivity, because there is no additional heat input, isn´t it?
The budget analyzer shows at least no additional one. But there is a higher temperature on the infiltration point at every end of pumping periods. Do you know the reason for this "springing" temperature. For example the temperature of the node is 5 °C by calculation of the open loop tool and springs within a time step (0.1d, 0.25d or 0.5d) after finish pumping to 7.5 °C.

Thanks.

Falk